jQuery.yihuUpload = { 
		createUploadIframe: function(id, uri)
		{
			//create frame
            var frameId = 'jUploadFrame' + id;
            var iframeHtml = '<iframe id="' + frameId + '" name="' + frameId + '" style="position:absolute; top:-9999px; left:-9999px"';
			if(window.ActiveXObject)
			{
                if(typeof uri== 'boolean'){
					iframeHtml += ' src="' + 'javascript:false' + '"';

                }
                else if(typeof uri== 'string'){
					iframeHtml += ' src="' + uri + '"';
                }	
			}
			iframeHtml += ' />';
			jQuery(iframeHtml).appendTo(document.body);
            return jQuery('#' + frameId).get(0);			
    	},
		
		createUploadForm: function(id, fileElementId, data)  
		{  
			var formId = 'jUploadForm' + id;  
			var fileId = 'jUploadFile' + id;  
			var form = jQuery('<form  action="" method="POST" name="' + formId + '" id="' + formId + '" enctype="multipart/form-data"></form>');      
			if (data) {  
				var _data = data.split('&');
				for(var i in _data){
					if (_data[i]) {
						var _d = _data[i].split('=');
						if(_d){
						jQuery('<input type="hidden" name="' + _d[0] + '" value="' + _d[1] + '" />').appendTo(form);
						}
					}
				}
			}  
			for (var i = 0; i < fileElementId.length; i ++) {  
				var oldElement = jQuery('#' + fileElementId[i]);  
				var newElement = jQuery(oldElement).clone();  
				jQuery(oldElement).attr('id', fileElementId[i]);  
				jQuery(oldElement).attr('name', fileElementId[i].name);  
				jQuery(oldElement).before(newElement);  
				jQuery(oldElement).appendTo(form);  
			}  
			//set attributes  
			jQuery(form).css('position', 'absolute');  
			jQuery(form).css('top', '-1200px');  
			jQuery(form).css('left', '-1200px');  
			jQuery(form).appendTo('body');  
			return form;  
		},
		
	  	handleError : function( s, xhr, status, e ) 		{
			// If a local callback was specified, fire it
				if ( s.error ) {
					s.error.call( s.context || s, xhr, status, e );
				}
			// Fire the global callback
				if ( s.global ) {
					(s.context ? jQuery(s.context) : jQuery.event).trigger( "ajaxError", [xhr, s, e] );
				}
		} ,
		 
	    ajaxFileUpload: function(s) {
	        // TODO introduce global settings, allowing the client to modify them for all requests, not only timeout		
	        s = jQuery.extend({}, jQuery.ajaxSettings, s);
	        var id = new Date().getTime()   
			var form = $.yihuUpload.createUploadForm(id, s.fileElementId,s.data);
			var io = $.yihuUpload.createUploadIframe(id, s.secureuri);
			var frameId = 'jUploadFrame' + id;
			var formId = 'jUploadForm' + id;		
	        // Watch for a new set of requests
	        if ( s.global && ! jQuery.active++ )
			{
				jQuery.event.trigger( "ajaxStart" );
			}            
	        var requestDone = false;
	        // Create the request object
	        var xml = {}   
	        if ( s.global )
	            jQuery.event.trigger("ajaxSend", [xml, s]);
	        // Wait for a response to come back
	        var uploadCallback = function(isTimeout)
			{			
				var io = document.getElementById(frameId);
	            try 
				{				
					if(io.contentWindow)
					{
						 xml.responseText = io.contentWindow.document.body?io.contentWindow.document.body.innerHTML:null;
	                	 xml.responseXML = io.contentWindow.document.XMLDocument?io.contentWindow.document.XMLDocument:io.contentWindow.document;
						 
					}else if(io.contentDocument)
					{
						 xml.responseText = io.contentDocument.document.body?io.contentDocument.document.body.innerHTML:null;
	                	xml.responseXML = io.contentDocument.document.XMLDocument?io.contentDocument.document.XMLDocument:io.contentDocument.document;
					}						
	            }catch(e)
				{
					$.yihuUpload.handleError(s, xml, null, e);
				}
	            if ( xml || isTimeout == "timeout") 
				{				
	                requestDone = true;
	                var status;
	                try {
	                    status = isTimeout != "timeout" ? "success" : "error";
	                    // Make sure that the request was successful or notmodified
	                    if ( status != "error" )
						{
	                        // process the data (runs the xml through httpData regardless of callback)
	                        var data = $.yihuUpload.uploadHttpData( xml, s.dataType );    
	                        // If a local callback was specified, fire it and pass it the data
	                        if ( s.success )
	                            s.success( data, status );
	    
	                        // Fire the global callback
	                        if( s.global )
	                            jQuery.event.trigger( "ajaxSuccess", [xml, s] );
	                    } else
	                        $.yihuUpload.handleError(s, xml, status);
	                } catch(e) 
					{
	                    status = "error";
	                    $.yihuUpload.handleError(s, xml, status, e);
	                }
	                // The request was completed
	                if( s.global )
	                    jQuery.event.trigger( "ajaxComplete", [xml, s] );
	                // Handle the global AJAX counter
	                if ( s.global && ! --jQuery.active )
	                    jQuery.event.trigger( "ajaxStop" );
	                // Process result
	                if ( s.complete )
	                    s.complete(xml, status);
	                jQuery(io).unbind()
	                setTimeout(function()
										{	try 
											{
												jQuery(io).remove();
												jQuery(form).remove();	
												
											} catch(e) 
											{
												$.yihuUpload.handleError(s, xml, null, e);
											}									
										}, 100)
	                xml = null
	
	            }
	        }
	        // Timeout checker
	        if ( s.timeout > 0 ) 
			{
	            setTimeout(function(){
	                // Check to see if the request is still happening
	                if( !requestDone ) uploadCallback( "timeout" );
	            }, s.timeout);
	        }
	        try 
			{
				var form = jQuery('#' + formId);
				jQuery(form).attr('action', s.url);
				jQuery(form).attr('method', 'POST');
				jQuery(form).attr('target', frameId);
				jQuery(form).attr('upname', s.upname);
	            if(form.encoding)
				{
					jQuery(form).attr('encoding', 'multipart/form-data');      			
	            }
	            else
				{	
					jQuery(form).attr('enctype', 'multipart/form-data');			
	            }	
	            jQuery(form).submit();
	        } catch(e) 
			{			
	            $.yihuUpload.handleError(s, xml, null, e);
	        }
			$('#' + frameId).load(uploadCallback	);
	        return {abort: function () {}};	
	
	    },
	
	    uploadHttpData: function( r, type ) {
	        var data = !type;
	        data = type == "xml" || data ? r.responseXML : r.responseText;
	        // If the type is "script", eval it in global context
	        if ( type == "script" )
	            jQuery.globalEval( data );
	        // Get the JavaScript object, if JSON is used.
	        if ( type == "json" )
	            eval( "data = " + data );
	        // evaluate scripts within html
	        if ( type == "html" )
	            jQuery("<div>").html(data).evalScripts();
	        return data;
	    },
		
		post:function(bizAction,param,successFn) 
		{
			param.bizAction=bizAction;
			$.ajax({
		        url : this.url,
		        data:param,
		        type : "POST",
		        dataType : 'json',
		        success : successFn
		    });
		}
		
};
